Many types of electronic systems include transistors such as complementary metal oxide semiconductor (CMOS) transistors. When such a transistor is turned on and off, a considerable amount of energy is dissipated as heat. Converting electrical energy to thermal energy causes multiple problems. First, converting to electrical energy to thermal energy in most cases is wasteful because thermal energy is not used to perform any useful work. If the system is battery-operated, because some of the energy is converted to a non-useful form, the battery will not last as long as it would had such energy not been wasted, or a larger, more expensive battery is needed to account for such losses. Second, the heat must be removed from the system which may require the use of heat sinks, fans, etc. Such heat dissipation equipment adds size, weight, and cost to the system.